A series of powerful gas blasts killed at least 27 people and injured up to 271 in the southern Taiwanese city of Kaohsiung, overturning cars and ripping up roads, officials said Friday.

The explosions sparked a massive inferno that tore through the city's Cianjhen district, sending terrified residents fleeing a huge ball of flames.

"The blasts late Thursday killed at least 27 people and left 271 others injured," the National Fire Agency said, adding that the wounded were being rushed to hospitals across the port city mostly with burn injuries.

Witnesses reported seeing dead bodies littered on the streets, with the fire raging through the night.

The explosions, believed to have been triggered by gas leaking from underground pipelines, were powerful enough to upturn cars and tear open paved roads. One street had been split along its length, swallowing fire engines and other vehicles.

"I saw fire soaring up to possibly 20 storeys high after a blast and fire engines and cars being blown away while around 10 bodies lay on the street," witness Johnson Liu told AFP.

"The explosions were like thunder and the road in front of my shop ripped open. It felt like an earthquake," Taiwan's Central News Agency quoted a witness as saying.

Residents were seen carrying the injured on makeshift stretchers as ambulances rushed to the scene and firefighters in yellow overalls began removing bodies from the area.

The fire agency said four firefighters were among those killed while 22 were injured.

"The cause of the gas leak is still not clear at this moment. We suspect the leaked gas could be propylene," said economic affairs minister Chang Chia-chu.

A Kaohsiung city government official said the blazes had mostly been extinguished or burned themselves out by mid Friday morning but a few fires were continuing.

"The local fire department received calls of gas leaks late Thursday and then there were a series of blasts around midnight affecting an area of two to three square kilometres," the fire agency said in a statement.

One local resident surnamed Peng said: "There was a heavy odour of gas and... then I heard explosions and saw fire spurting from a store."

"My house shook as if there were an earthquake and the power went out," she was quoted as saying by the Taiwan Central News Agency.

Local media reported that emergency rooms in Kaohsiung city hospitals were packed with casualties and officials warned that the death toll was expected to rise.

The local government were evacuating more than 1,100 residents from the impacted areas to schools and shelters as they tried to locate the source of the leaks and warned people to stay away.

The military dispatched around 1,400 soldiers to the scene to help with the disaster effort.

It was the second gas blast in Kaohsiung in recent years. In 1997, an explosion killed five people and injured around 20 when a team from Taiwan's state-run Chinese Petroleum Corp. (CPC) tried to unearth a section of gas pipeline in a road construction project.

It was the second disaster to strike Taiwan in just over a week, after a TransAsia Airways plane crashed with the loss of 48 people last Wednesday. AFP